For resin molded articles, it is commonly known that glass fibers, carbon fibers, mica, glass beads, glass flakes or the like are added as a filler to a matrix resin to achieve reduction in warping and deformation and/or enhancement of mechanical strength. For such a resin molded product, it has been considered preferable to surface-treat the filler with a silane coupling agent or the like to enhance the adhesion between the matrix resin and the filler and thereby further increase the mechanical strength of the resin molded article.
For example, in relation to resin molded articles whose matrix resin includes a polyolefin such as polypropylene, techniques for enhancing the adhesion between the matrix resin and a filler have been proposed. For example, Patent Literature 1 describes a technique that uses mica as a filler for polyolefin reinforcement and that includes treating the surface of the mica with an organosilane compound to enhance the adhesion between the mica and a polyolefin used as a matrix resin and adding specific compounds (a bismaleimide compound and an organic peroxide) to the matrix resin to further improve the adhesion.